Creation: First proposed to be assigned to Appalachian Corridor H in 2001, from Strasburg west to I-79 Weston, WV. Per Dan F, US 48 was first posted in 2003 as an addition to VA 55 from I-81 west to West Virginia.
Adjustments:None
Improvements: Upon designation, US 48 was fully paved; no multilane segments
Posted: Fully posted; Error US 48 posting exists at Borden Mowery Dr which is east of I-81.
Multiplexes: VA 55 (14.23 mi)
Legislative names: John Marshall Highway (9/7/33 designation predates US 48);
Other names: Wardensville Pike (Frederick Co)
Scenic Byway: Frederick SR 600 to I-81 (since 6/12/97);
Comments: Corridor H is entirely a West Virginia endeavor at this point. Virginia has shown no interest in making US 48 an expressway-type route. It has posted the route for continuity with West Virginia and that's about it. As of late 2017, Corridor H has been constructed as nearly entirely new alignment from Wardensville WV west to Davis. West Virginia had been posting US 48 on each new segment as it opened on the road heading westward, but when the route was built to Davis they added US 48 shields along WV 32, US 219, and US 33 for the entirety of the Corridor H designation.
US 48 did not appear on a state official map until the 2016 issue, but it had been in several Rand McN issues and was explicitly shown in traffic logs since 2003.